cement topping and waterproof membrane question

[planc]

We removed the bituminous membrane sheet and the topping above the membrane because of some leaks. You can still see the old membrane on the upper sides at the edges not yet teared or pulled up. (and the lower left side whose topping were not chipped).

but you can see, the membrane has no separate drain on each own. It drain is taken by the concrete topping above. But ever years when the topping cracks or the membrane cracks. Its difficult to tell them from each other.

In this case what you guys do? I heard using insulation tapered is put below the membrane to slope it to the drain, but won't water get into the inside of the tapered insulation as well? What kind of tapered insulation is used. Share some picture. Thanks.

 

[planc]

https://www.youtube.com/shorts/s65u2umkFm8

In the video above, My workers pulled up the 7 year old bituminous membrane easily. Is such torch on membrane supposed to be that easy to remove, or was it not property done during the torch on? Just before it they removed the 2" screed/topping whose purpose is to protect the membrane.

What is your experience on it?

Now I plan to use this so called Sista D100plus acrylic waterproof and sealer (with built in UV protection) painted over the roughly 24 square meter now bare balcony concrete deck as waterproof. The store said it was their bestselling, and can be applied over the concrete. But in the product descriptions, it appears to be used as sealants. What is the behavior if you apply on the entire deck surface as most are doing?

And is it difficult to remove later (like sanding every surface) when there is still leak or I want to replace to other kinds of waterproof?

I don't want workers to handle Polyurethane waterproof because they always use their fingers on the liquid. What is the best waterproof material have you tried on a concrete deck?

 

[BridgeSmith]

It looks to me like there's some exposed reinforcing (wire mesh). It may need a concrete overlay before the membrane or sealer is put down. The overlay could be done with a sand topping mix, or if the budget allows, a silica fume or latex modified concrete would be far better. Could be the easiest way to get the slope required, also.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[planc]

The exposed wire mesh is part of the waterproof topping (above the membrane) being chipped off.

Here worker was putting grease to the chipping hammer.

The reason the topping is being chipped off is to remove the bituminous membrane below the topping and replace it with similar or other kinds of waterproofing.

But removing the topping and membrane removed the waterproofing exposing the original slab with water ponding in the bare slab.

We need to put slope underneath the membrane itself. But if you use sand, topping mix, or silica fume or latex modified concrete, won't the water pond beneath it and go to the membrane and find weakness and go to the slab? The main question is what material to use between the membrane and main slab underneath to create the slope?

The old contractor made a mistake (as most do). The top of drain was with respect to topping slab and not membrane structural slab. The issue with this is water will leak below topping slab, unless it is designed as a water tight slab (including connections at its edges), and it will pond. a 2" topping will crack for sure.

Technically. Water will travel through these cracks and come to rest on the membrane. I found out (something most workers or architects don't even know) is that the weight of 2" of concrete topping (above the membrane) does not prevent water from finding its way into every little available crack and crevice in the topping. Since the only drainage one was providing was at the top of the topping level, where does the water that is on the membrane go, how does it get removed from the system? It doesn't, it sits there and works its powers of damage corroding steel.

That technical aspect clarified. I need to find some material to create the slope between the membrane and the main slab, before the concrete topping (above the bituminous membrane) will be put again. What material?

 

[HTURKAK]

Apparently , IMO, you need a slope concrete and membrane waterproofing..

You may look to the following doc. and choose one of the dtails applicable for your specific case..

https://www.sika.com/dms/getdocument.get/59770834-c41e-4d8a-ab94-ca8a9aa18001/glo-cool-roofs.pdf

https://usa.sika.com/sarnafil/en/downloads/typical-roofing-details.html

 

[planc]

I looked at the docs. But I can't find the specific sika material that you can put on already *existing flat slab* but with a very small area ponding with water (like above photo shows). Also we prefer not to use any membrane because we don't want more additional dead weight of the waterproof membrane topping. Can you think of an adhesive or mortar level that you can just put on the low area (and it can bind as great as original concrete) so that water won't pond, then just put acrylic or liquid waterproof?